In order to be successful in the marketplace, document counters, which are used to count paper money and other documents, should be capable of operating at low and high speeds, while accurately counting and batching documents, which may include currency and food coupons. Prior to processing documents in standard document counters, the documents are manually separated into stacks of like denomination or type. In developing a comprehensive document counter, it would be desirable for the document counting and batching apparatus to provide visual running totals of the pieces and value of the currency counted and/or batched, to be capable of detecting errors such as counterfeit suspects, doubles, chains, off-widths, and half documents, and the document counter should be designed to stop when an error is detected to permit the operator to correct the detected error. As an additional feature, it would be desirable for a document counting and batching apparatus to be capable of (i) stand alone operation, (ii) connection as a slave to a host, such as a personal computer, or (iii) stand alone operation with connection to a printer for a print-out of totals. It would further be desirable for a document counter to maintain and to selectively display or print several types of counts and totals divided into operator-designated categories. One category would be a piece count with no designation of denomination. Other categories (such as 1, 2, 5, 10, 20, 50, and 100 dollar denominations) would be piece counts of operator-designated denominations. It would be desirable relative to these categories to display a running piece count of the first category, and running piece counts multiplied by the denomination to yield the value of denominations counted for each of the other categories. Also, it would be desirable to be able to display, or to display and to print, the accumulated totals for each category in the same or similar format as for running total displays. Further, it would be desirable to display and/or print the grand total value of the values of all of the denomination categories counted.
Document counting and handling devices are known which count, verify and stack a particular type of document, such as U.S. currency. Among such devices are those that utilize analog comparator circuits to verify whether the optical and magnetic characteristics of a document falls within thresholds set by discrete electronic components which bias the comparator circuits. In order to adapt such devices for counting and verifying documents which vary with respect to optical or magnetic properties, it is necessary to manually adjust the biasing components of the analog comparator circuits. However, the particular combination of verification tests that may be implemented in a document counting device of the prior art, which is adapted for one type of document such as U.S. currency, may not be suitable for another type of document such as coupons, food stamps, or foreign currency. Accordingly, it would be desirable to provide a control system for a document counting apparatus in which verification tests can be selectively enabled and in which verification thresholds can easily be selected to conform to the characteristics or properties of a variety of documents.
It has been found that accurate verification of documents based on optical and magnetic properties of documents in a high-speed document counting device is complicated by the presence of electrical noise from a variety of noise sources within the counting device. In order to increase the reliability with which documents are verified as genuine, it would be desirable to provide a system for document verification which is essentially immune to the influence of such electrical noise.